diff --git a/core/src/com/unciv/logic/city/CityInfo.kt b/core/src/com/unciv/logic/city/CityInfo.kt
index 37ae8238f8935..86a46b30f701d 100644
--- a/core/src/com/unciv/logic/city/CityInfo.kt
+++ b/core/src/com/unciv/logic/city/CityInfo.kt
@@ -322,10 +322,11 @@ class CityInfo {
                 }
             }
         }
-        
+
+        val freeBuildings = civInfo.civConstructions.getFreeBuildings(id)
         for (building in cityConstructions.getBuiltBuildings()) {
             // Free buildings cost no resources
-            if (building.name in civInfo.civConstructions.getFreeBuildings(id))
+            if (building.name in freeBuildings)
                 continue
             for ((resourceName, amount) in building.getResourceRequirements()) {
                 val resource = getRuleset().tileResources[resourceName]!!
diff --git a/core/src/com/unciv/logic/civilization/CivConstructions.kt b/core/src/com/unciv/logic/civilization/CivConstructions.kt
index f856210f968fd..3a9ba4dbf4068 100644
--- a/core/src/com/unciv/logic/civilization/CivConstructions.kt
+++ b/core/src/com/unciv/logic/civilization/CivConstructions.kt
@@ -59,7 +59,10 @@ class CivConstructions {
     fun getFreeBuildings(cityId: String): HashSet<String> {
         val toReturn = freeBuildings[cityId] ?: hashSetOf()
         for (city in civInfo.cities) {
-            toReturn.addAll(city.cityConstructions.freeBuildingsProvidedFromThisCity[cityId] ?: hashSetOf())
+            val freeBuildingsProvided =
+                city.cityConstructions.freeBuildingsProvidedFromThisCity[cityId]
+            if (freeBuildingsProvided != null)
+                toReturn.addAll(freeBuildingsProvided)
         }
         return toReturn
     }
diff --git a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
index 5eb4e0f24ea4d..83da42c537f2e 100644
--- a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
+++ b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
@@ -1055,8 +1055,9 @@ class CivilizationInfo {
 
     fun addUnit(unitName: String, city: CityInfo? = null): MapUnit? {
         if (cities.isEmpty()) return null
-        val cityToAddTo = city ?: cities.random()
         if (!gameInfo.ruleSet.units.containsKey(unitName)) return null
+
+        val cityToAddTo = city ?: cities.random()
         val unit = getEquivalentUnit(unitName)
         val placedUnit = placeUnitNearTile(cityToAddTo.location, unit.name)
         // silently bail if no tile to place the unit is found
diff --git a/core/src/com/unciv/models/ruleset/Building.kt b/core/src/com/unciv/models/ruleset/Building.kt
index 68e3231cd34e9..89b06770afbff 100644
--- a/core/src/com/unciv/models/ruleset/Building.kt
+++ b/core/src/com/unciv/models/ruleset/Building.kt
@@ -792,13 +792,15 @@ class Building : RulesetStatsObject(), INonPerpetualConstruction {
 
     fun isSellable() = !isAnyWonder() && !hasUnique(UniqueType.Unsellable)
 
-    override fun getResourceRequirements(): HashMap<String, Int> {
+    override fun getResourceRequirements(): HashMap<String, Int> = resourceRequirementsInternal
+
+    private val resourceRequirementsInternal: HashMap<String, Int> by lazy {
         val resourceRequirements = HashMap<String, Int>()
         if (requiredResource != null) resourceRequirements[requiredResource!!] = 1
         for (unique in uniqueObjects)
             if (unique.isOfType(UniqueType.ConsumesResources))
                 resourceRequirements[unique.params[1]] = unique.params[0].toInt()
-        return resourceRequirements
+        resourceRequirements
     }
 
     override fun requiresResource(resource: String): Boolean {
diff --git a/core/src/com/unciv/models/ruleset/unit/BaseUnit.kt b/core/src/com/unciv/models/ruleset/unit/BaseUnit.kt
index 8ba5b9c9c64a4..ffe569861f2e6 100644
--- a/core/src/com/unciv/models/ruleset/unit/BaseUnit.kt
+++ b/core/src/com/unciv/models/ruleset/unit/BaseUnit.kt
@@ -582,13 +582,15 @@ class BaseUnit : RulesetObject(), INonPerpetualConstruction {
 
     fun movesLikeAirUnits() = getType().getMovementType() == UnitMovementType.Air
 
-    override fun getResourceRequirements(): HashMap<String, Int> {
+    override fun getResourceRequirements(): HashMap<String, Int> = resourceRequirementsInternal
+
+    private val resourceRequirementsInternal: HashMap<String, Int> by lazy {
         val resourceRequirements = HashMap<String, Int>()
         if (requiredResource != null) resourceRequirements[requiredResource!!] = 1
         for (unique in uniqueObjects)
             if (unique.isOfType(UniqueType.ConsumesResources))
                 resourceRequirements[unique.params[1]] = unique.params[0].toInt()
-        return resourceRequirements
+        resourceRequirements
     }
 
     override fun requiresResource(resource: String): Boolean {